A sensor device includes a sensor chip and a circuit chip, which are laminated through an adhesive material and connected through a bonding wire. This type of sensor device has a construction in which the sensor chip is laminated and adhered onto the circuit chip through the adhesive material, and the sensor chip and the circuit chip are connected to each other through the bonding wire.
For example, a structure for mounting the sensor chip onto the circuit chip through the adhesive material of a film shape is proposed as such a sensor device to reduce an output change with respect to a temperature change of the sensor chip for the purpose of a reduction in thermal stress of its joining portion. This structure is disclosed in, for example, U.S. Pat. No. 6,593,663.
However, in the structure of the sensor device of this kind, when the adhesive material such as the film shape adhesive material for adhering a portion between the chips has low elasticity, the rigidity of the joining portion of the sensor chip and the circuit chip is reduced, so that the sensor chip is easily greatly displaced by an impact from the exterior.
Therefore, the problems that the bonding wire for electrically connecting both the chips is easily deformed with respect to the deformation of this sensor chip and is disconnected in its turn, are caused.
In particular, in the case of a physical amount sensor of a capacity type for converting a physical amount into a capacity change by the sensor chip and detecting the physical amount, the parasitic capacity between adjacent wires, or between the wires and the chips affects sensor characteristics.
Therefore, the deformation of the bonding wire caused by excessively displacing the sensor chip causes a change in the above parasitic capacity as well as mechanical deformation including the disconnection of the wire. Therefore, the problem of a change in sensor chip characteristics is caused.